Back water overflow device for sewers



May 17, 1960 HINKSQN ETAL 2,936,775

BACK WATER OVERFLOW DEVICE FOR SEWERS Filed April 28, 1959 W 08 mm H0 H M M 0U RC United States PatentO BACK WATER OVERFLOW DEVICE FOR SEWERS Robert H. Hinkson and Clyde M. Hopkins, Walnut Creek,

CaliL, assignors to Central Contra Costa-Sanitary Distrlct, Walnut Creek, Cali, :1 political subdivision of California Application April 28, 1959, Serial No. 809,442

4 Claims. (Cl. 137- 363) This invention relates to a back water overflow device for sewers and particularly to a device for relieving liquid from a sewer line for the protection of property which might be damaged when the line carries fluid in excess of its intended capacity.

Where sewer facilities include main line and side sewers, which are portions of the main line communicating with buildings to be served, it sometimes occurs that a home or building to be served is lower than the elevation of the nearest upstream structure or to the service inlet capable of relieving pressure in the main line. Therefore, in the event of a downstream stoppage or other cause of excess liquid, such as storm water entering the sewer, overflow occurs through the outlets in the building occasioning serious damage.

One methodof preventing such damage is to provide an outlet near the building and lower in elevation than the lowest fixture outlet therein which is connected to the sewer. This is accomplished by providing a riser or vertical pipe between the side sewer and the surface of the ground and placing a check valve therein at ground level to permit escape of liquid at a point lower than outlets within the building.

It is to the construction of such an overflow valve or device that the present invention is particularly directed. It is an object of the invention to provide a one-way overflow device of the kind described above capable of forming a liquid and gas tight seal and opening under fitting extends. An annular valve seat 14 of rubber or other; resilient material is secured within the fitting 10 as by'a plastic or adhesive substance illustrated at 15. A spherical valve element 16 cooperates with the seat 14, shown in Fig. I, normally to seal the passageway through the fitting 10 against the escape of noxious gases:

' The valve element 16 is of lighter than water construe 7 foreign matter into the chamber above the valve.

tion and may be in the form of a hollow sphere of cop per or other material. It is suspended as by a chain '17 from the center of a cover 18 normally resting on top of thefitting 10 and closing it against the entrancelgf e cover 18 is hinged to the fitting by means which permit it to rise vertically upwardly a limited distance as illustrated in Fig. 2, or to hinge to a fully opened position in the manner shownin Fig. 3 where the cover is shown partially opened. This is accomplished through a hinge part 19 on the cover with an elongated downwardly loop 20 embracing a hinge pin 21 which extends between ears 22 formed at the end of a strap 23 encircling the upper end of the fitting 10.

In operation, upon the event of excessive liquid in the I line threatening to flood a buildingflhe valve element 16 pressure to accommodate full flow of the pipe sizes in which it is used. A further object is to provide such a device which closes automatically after flow with protection against the entrance of dirt or other foreign matter and with all of its parts-readily accessible for flushing with fresh water after it has served its purpose.

Further objects and advantages of the invention are made apparent in the following specifications wherein reference is made to the accompanying drawing illustrating a preferred form of the invention:

In the drawing:

Fig. 1 is a central vertical sectional view of an overflow device embodying the present invention in its normal closed position.

Fig. 2 is a view like Fig. 1 illustrating the position of the parts of the device during discharge of liquid thereth-rough,

Fig. 3 is a similar view illustrating the position of the parts during flushing of the device for cleaning purposes, and

Fig. 4 is a plan view of a collar and binge structure which forms a part of the invention.

The device, as illustrated in Figs. 1 to 3, comprises a cylindrical body 10 of ceramic or other material of which a sewer line may be constructed with a lower end 1'1 of reduced cross section to fit within the bell end of a pipe 12. The pipe 12 is representative of the upper end of a riser communicating with a side sewer just below the surface of the ground level shown at 13 above which the is lifted by pressure and floated to the position of Fig. 2 where it engages and opens the cover 18 in the manner shown to permit escape of excess liquid. Since the cover has not been swung upon its hinge to a fully opened position, it settles back to its protecting position immediately when the flow ceases and the valve element 16 again forms a seal with the seat 14 unless foreign material has become lodged on the seat.

Inspection and cleaning should take place after each occasion which actuates the valve and this is accomplished by raising the cover through the position shown in Fig. 3 to a fully opened position to permit flushing of the device with clear water.

In some cases of overflow, the force of the liquid may be so great as to exceed the capacity of the device opened to the position of Fig. 2 and swing the cover to the position of Fig. 3 or further. In this event, the valve element is prevented from lodging between the cover and the upper end of the fitting 10 by the chain 17, the length of which is such as to limit the outward movement of the valve element 16 to the position illustrated in dotted lines in Fig. 3. When it descends from this position, it must enter the valve chamber rather than rest on the upper edge of the fitting 10 where it could prevent closing of the cover 18.

We claim:

1. A back water overflow device for sewers which comprises in combination with a vertical pipe connected with a sewer line and opening above ground, a gravity ball check valve in said pipe including a seat adjacent the opening, said valve including a floatable valve ball between said seat and opening, said ball being normally gravity biased against said seat to control flow through said pipe, a cover hinged adjacent the opening to overlie the opening and the valve ball, and flexible means connecting the ball to the cover.

2. A back water overflow device for sewers which comp-rises in combination with a vertical pipe connected with a sewer line and opening above ground, a gravity ball check valve in said pipe including a seat adjacent the opening, said valve including a floatable valve ball between said seat and opening, said ball being normally gravity biased against said seat to control flow through said pipe, a cover hinged adjacent the opening to overlie the opening and the valve ball, and flexible means connecting the ball to the cover, said flexible means being of limited length to prevent escape of the ball from the pipe.

ageem'n 3. A back water overflow device for sewers which comprises in combination with a vertical pipe connected with a sewer line and opening above ground, a gravity ball check; valve in said pipe including a seat adjacent the opening, said valve including a floatable valveball betweensaid seat and opening, said' ball being normally gravity biased against said seat to control flow through said pipe, a cover hinged adjacent the opening to overlie the opening and the valve ball, and flexible means connee-ting the ball to the cover, said ball being lighter than water to enable it to float from its seat and engage the cover to openit.-

4. A back water overflow device for sewers which comp-rises; in combination with a vertical pipe connected with a sewer line and opening above ground, a gravity ball check-valve in said pipe'including a seat adjacent the opening, said valve-including a floatable valve ball between said seat and opening, said ball being normally gravity biased against said seat to control flow through said pipe, a cover hinged adjacent the opening to overlie the opening and the valve ball, and flexible means connecting the ball to the cover, said cover having a hinge including a pin and slot to enable it to rise vertically a limited distance and to swing to a full open position; 7

References Citedin thefi l e of this patent UNITED STATES PATENTS 

